So now you know…

This from

British scientists believe they have cracked the answer to the age-old question of which came first, the chicken or the egg?

Researchers have found that a protein called ovocleidin (OC-17) is crucial in the formulation of eggshells, and it is produced in the pregnant hen’s ovaries, the Daily Express reports.

Therefore, the answer to the conundrum must be that the chicken came first.

Using a high-tech computer to look at the molecular structure of a shell, the team of scientists from the Universities of Sheffield and Warwick found that OC-17 acts as a catalyst, kick-starting the conversion of calcium carbonate in the chicken’s body into calcite crystals.

They make up the hard shell that houses the yolk and its protective fluids while the chick develops.

“It had long been suspected that the egg came first but now we have the scientific proof that shows that in fact the chicken came first,” said Dr Colin Freeman, from Sheffield University.

“The protein had been identified before and it was linked to egg formation but by examining it closely we have been able to see how it controls the process.”

But the researchers have not yet got an answer to how the protein-producing chicken existed in the first place.

I may have more to say about this later…  I don’t quite see how this is “proof” that the chicken came first.

Update:  Here’s PZ Myer’s take on this.  In a nutshell:

You simply can’t make the conclusion the reporter was making here. The species ancestral to Gallus gallus laid eggs, the last common ancestor of all birds laid eggs, the reptiles that preceded the birds laid eggs…the appearance of egg laying was not coincident with the evolution of ovocleidin. The first chicken that acquired the protein we call ovocleidin now by mutation of a prior protein also hatched from an egg.


2 Responses to So now you know…

  1. Gavin says:

    All these scientists have done is find a technical way of telling us what we already know – that a chicken is needed if you want an egg. However they have failed to answer the question because an egg is still required if you want a chicken.

    This conundrum doesn’t take too much evolutionary knowledge to work out. Certainly not a supercomputer…

    All you need to do is start from the beginning: the single celled organism. We then follow it through evolution to the chicken. Clearly somewhere early in this chain, well before becoming a chicken, it ‘decided’ to use eggs to reproduce.
    As the creature evolves into a chicken, the way it produces eggs would also evolve and the eggs gain a shell.
    As an example we can look at smaller, less complex creatures that use this. We find tiny eggs that do not have a ‘protein shell’ – they are soft and easy to break. Proving that the protein shell is not required for this method of reproduction and disproving the evidence provided by these british scientists.

    Using this evolutionary thinking, we can come to the conclusion that the chicken and egg evolved together. The chicken certainly didn’t come first as the scientists claim.

  2. hilaryml says:

    Yeah it seems like the researchers involved here are just trying to dress their research up with a quirky and fun angle that has been picked up by the media. Because its hardly surprising news that there are proteins in chicken ovaries that trigger the development of eggs.

    I was out of town most of yesterday so didn’t have a chance to blog about this properly, so I’ve added a link to PZ Myer’s take on it – he hits the nail on the head when he says “the appearance of egg laying was not coincident with the evolution of ovocleidin (OC-17)”.

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